Project summary Hospitals should do the sick no harm. That noted, modern day pediatric intensive care units (PICUs) are not healing milieus. Immediately upon admission to the PICU, the child?s daily routine and sleep patterns are replaced by a well-intended but not patient-centered PICU routine. Our interprofessional team believes that PICU care and environments can be modulated to sustain a young child?s circadian rhythm (CR) and support their physiological resilience and capacity to heal. The first step in our paradigm-changing program of research is to use the R21 mechanism to pilot-test RESTORE resilience (R2), a 7-item individualized CR-restoring bundle, in two separate PICUs using a pre- posttest design. Specifically, after PICU admission, parents will be interviewed to inform the creation of an individualized chronotherapeutic bundle to include (1) focused effort to replicate the child?s pre-hospitalization daily routine (bedtime/wake time, bedtime/arousal routine, nap time, feeding schedule, active periods) in the PICU, (2) cycled day-night lighting and modulation of sound to match the child?s routine, (3) minimal yet effective sedation using a nurse-implemented goal-directed sedation plan (RESTORE), (4) night fasting with bolus enteral daytime feedings, (5) early progressive exercise and mobility (PICU Up!), (6) continuity in nursing care, and (7) parent diaries. We believe that critically ill pediatric patients managed per RESTORE resilience will experience less disruption in circadian rhythm as evidenced by improved day and night rest-activity patterns than patients receiving usual care. Our primary outcome is the circadian activity ratio (daytime activity/total 24-hr activity). Secondary outcomes will include salivary melatonin levels; EEG slow-wave activity; R2 feasibility, adherence, and system barriers; levels of patient comfort: PICU days free of pain, agitation, delirium, iatrogenic withdrawal syndrome; PICU exposure to sedative medications (total dose and length of exposure); time to physiological stability (time on vasoactive medication, duration of mechanical ventilation, PICU and hospital lengths of stay); and parent perception of being well-cared-for. Results of this pilot study will be used to inform the design of an adequately powered multicenter randomized trial of RESTORE resilience.